Low-density parity check (LDPC) codes are employed to protect communication via noisy physical channels such as copper wires or an air interface. LDPC codes add an extra amount of redundant information to a coded signal communicated via a physical channel in order to enable reconstruction of errors that are present due to noise on the physical medium (Forward Error Correction, FEC).
Different techniques of decoding LDPC-encoded signals are known, e.g., the so-called min-sum algorithm, see, e.g., A. Darabiha et. al., A Bit-Serial Approximate Min-Sum LDPC Decoder and FPGA Implementation in IEEE Proc. Circuits and Systems (2006): section A “LDPC codes and min-sum decoding”. Various decoding techniques rely on check nodes and bit nodes which constraints of the LDPC-code and bits of the result signal, respectively. Typically, bit node values and check node values are alternatingly updated for each one of a number of iterations. Iterations are aborted upon convergence.
Reference implementations of the min-sum algorithm face certain restrictions and drawbacks. E.g., a time to convergence can be comparably long, thus limiting a data throughput and/or requiring considerable amounts of calculation power. Further, it has been observed that applying the min-sum algorithm in certain scenarios—in particular with significant noise is present on the physical channel—can even prevent the algorithm from converging at all.